A pasty or film-shaped anisotropic conductive material has been widely known. In the anisotropic conductive material, a plurality of conductive particles is dispersed in a binder resin.
In order to obtain various kinds of connected structures, the above-mentioned anisotropic conductive material is used for the connection of a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), the connection of a semiconductor chip and a flexible printed circuit board (COF (Chip on Film)), the connection of a semiconductor chip and a glass substrate (COG (Chip on Glass)), the connection of a flexible printed circuit board and a glass epoxy board (FOB (Film on Board)), and the like.
As an example of the above-mentioned anisotropic conductive material, in the following Patent Document 1, a conductive adhesive containing an epoxy-based adhesive having a fluxing action and SnBi-based solder powder has been disclosed. In Patent Document 1, it has been described that the content of the solder powder suitably lies within the range of 10 to 90% by weight, preferably 40 to 80% by weight, relative to 100% by weight of the conductive adhesive. Moreover, in Patent Document 1, the epoxy-based adhesive having a fluxing action is exemplified by an epoxy-based adhesive containing an epoxy resin, a hardener and an organic acid. Moreover, in Patent Document 1, it has been described that the conductive adhesive is usable even if a small amount of succinic acid, malonic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, or the like is added as an auxiliary activator. Moreover, in the Example of Patent Document 1, as the above-mentioned organic acid and the above-mentioned auxiliary activators, 2,5-diethyladipic acid, succinic acid, glutaric acid, and malonic acid are used.
In the following Patent Document 2, a solder paste containing flux and solder particles has been disclosed. The above-mentioned flux contains a silicone resin and an organic acid or an organic acid salt. In Patent Document 2, with regard to the quantitative ratio between the flux and the solder particles, it has been described that the content of the flux suitably lies within the range of 5 to 60 parts by weight relative to the content of the solder particles of 40 to 95 parts by weight. In the Example of Patent Document 2, as the organic acid or the organic acid salt, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, hydroxyacetic acid, or monoethanolamine succinate is used.
On the other hand, in the following Patent Document 3, flux for soldering which contains an activator obtained from a dibasic acid with a molecular weight less than or equal to 250 and a monobasic acid with a molecular weight greater than or equal to 150 and less than or equal to 300 has been disclosed.
In the following Patent Document 4, a solder paste which contains an alcohol having at least two or more OH groups as a base agent for flux, contains an organic acid as an activator for flux, and contains metal powder has been disclosed.